Electronic static discharge apparatus



July 28, 1953 A. J. CHECK 2,647,223

ELECTRONIC STATIC DISCHARGE APPARATUS Filed May 14, 1948 ?'6- INVENTOR- fl/ex J (r 766k.

patented July 28, 19

236141223 emoieitomo sm'rlc meme; APBARA'DUS AlxiJl Checli, Struthers, Ohio. Appliation May "1 4, 1948i s hliufl Ni). 265958) 2! (31mins.- (cram-zit 1-a Thissinvention'relates toidevicesffordischarging? electrostatic; fields; and more particularly to: a: device. for electronically discharging? an electroestatic 'fielclzt The principall object; cfa' the inventlorr is the) 5 particularly fromselvent circulated through a dry 7 cleaning imachinel- This invention is a continuation in partuot my; patent, application Serial N0. 790 ,913 ;on .Ground-t-- lng: Electrode for" Dry Cleaning Machines-, filegll December 10, 194-7, whichhas;becomeabandonecl; 2.;

The. electronic static dischargeapparatus shown and-rdescribedllierein. is particularlyi useful in continuouslpdischargingvstatic. electricityfromfiuiclszsuch assolventsemployed in. dry, cleaning operationsanditherehy,preventingthe.redepositae 2 tion ofsoil particles in:garmentsbeingicleaned. in the-solvent-- As iswelliknown. inithe art'of, drylcleaning, the so-called graying of garments. occurs periodically during" the. Wasliirlgl. or: actual: dry cleaning,- operation and. asi's also knownin'the art the periodic grayingoi .'fgafi ments has been attributed to, many and" varmus causes.v Forexample the presence 01 abs (2 of moisture in the. garments andlor dry, cleaning solvent has been set forth asacontributingpause by various dry cleaning authorities andtliepr'o posal' heretofore made that by controlling the moisture content of the garments and/or the solvent; the incidents of graying m'ightbe'recluce'cl. y X N Itis also Well lrhownlthat the graying is di rectly caused byth'e redepositationf of rniii't'itc soil" particles in the garments in-the cry cleaning machine" usually subsequent their'dnitia'l re movalfrornth'e garments; For example, a dry cleaning machine with new solvent charged retainedi therebygwhile'. at; other "times a: main oft the soil Qfillltl016$ will; be redepesitedx in; the. garments: in the dry-' cleaning. machine espite. theicontinuous circulation of the solventithrongli tire machinezandlits;associatedifilten h p z The basic causeof the redepositation' v or soil; is believed; to: lie; int the: creatiom of electrostatic.

filter-sl in; the dryy cleaning; solvent; the garn'ients; inthe; cleaning; machine inz the solvent, 1 innthe-scillparticlessnspended iIIithQfiOlVIl-titfilf;

tlie rnovementlofithe garments, thesolveiitia'ntlf thcrsoilipatticlelslasioccasioned ofsthe erye eanmg machine:- A I of; grayingeccurs dnriii g theact al; are clean; ing operation, I the normal aciirnula on. of nee trostaticifields in thesolventland 'tl'lesoilha'r'ticle's, therein is believed; to, he 1 responsible, as. their presence in the electrostatic fields, elreet; an tract ,theim-im teisoil, particles fromtheir. normal suspension in-ltlie solv; filth. thegarime'nts'where thegv are. retained, with: he eve-my- 61s: triputed umrerm y gra appe ahce'...

clar'iiii; machine ectivly mmense tyr completely ei mirmting'th resistance the grounding; lectrlo e its grcued circiiit mmcgh the .c-i'stabl Inenfitherein of relatively sma reireet owed-groun p The pr sem diseiqsure relates to, t'lii impro" ifiiifi andspecific-any" to th eSttki "slimnt 'df a grounding electrode and groundic prisrtmnew mthe" solvent" ccnr'inu l at the cleamn machine and prov: e

y generated within the dry eia-fim '"ihe;the solveiititherein or-"th can mentstnerem: I

appear a theclsorip a p i hv ntrori resides ifrthe comhifiatiofrand ar use ez'it df-ipar nth th cletails' onbeing understood that changes in the precise embodiment of the invention herein disclosed can be made within the scope of what is claimed without departing from the spirit of the invention.

The invention is illustrated in the accompanying drawing, wherein:

Figure 1 is a plan view of the electronic static discharge apparatus with parts in cross section and parts broken away.

Figure 2 is a diagrammatic illustration of the electronic static discharge apparatus.

Figure 3 is a plan view of a preferred form of mounting of the electronic static discharge apparatus on a dry cleaning machine.

Figure 4 is a plan form of mounting of the electronic static discharge apparatus on the dry cleaning machine.

By referring to the drawings and Figures 1 and 2 in particular it will be seen that an explosion-proof box ID has been illustrated in cross section and that it partially encloses an end II of a grounding electrode I2, the majority of the grounding electrode I2 extending outwardly beyond the exterior of the explosion-proof box l and adapted for mounting within a fitting such as a T I3 through which dry cleaning solvent may be circulated. Disposed within the explosion-proof box I0 there is a unit I4 comprising, as may be seen by referring to Figure 2 of the drawings, a transformer including a primary winding I5 and a secondary winding I6. The secondary winding I6 of the transformer is in electrical connection with a rectifier which may be either full wave or half wave, as desired, the full wave being preferred, and a condenser I8 connected across the terminals of the rectifier H.

A power supply for the primary winding I5 of the transformer comprises a pair of circuit wires I9 and are adapted to be connected to a 110 volt A. C. circuit. The secondary winding IB of the transformer provides 3 volts A. C. which is converted by the rectifier H to 3 volts D. C. The positive terminal of the rectifier is connected by means of a circuit wire 20 with a tap 2| on the end II of the grounding electrode l2 and a circuit wire 22 connected with the negative terminal of the rectifier I! and with a resistance unit of approximately 200,000 ohms indicated in the drawing by the numera1 23. The resistance unit 23- is connected by a circuit wire 24 with a ground tap 25 which comprises a screwlike body member 26 threadably engaging an orifice in the explosion-proof box III. A ground wire 2! establishes connection between the ground tap 25 and the ground. A circuit wire 28 connects with the ground tap 25 and with a tap 29 on the end II of the grounding electrode I2 and inwardly with respect to the tap 2| heretofore described.

It will thus be seen that when the primary winding I5 of the transformer in the unit I4 is energized as by connection with a 110 volt A. C. power source, 3 volts A. C. will be obtained from the secondary winding I6 thereof. The rectifier I| connected with the secondary winding I6 of the transformer converts the 3 volt A. C. to 3 volt D. C. and the positive tap terminal of the rectifier I1 is connected directly to the tap 2| on the grounding electrode I2. Thus, a positive charge is imparted to the electrode I2 and at the same time the electrode I2 is grounded by means of the circuit wire 28 connecting with the tap 29 on the electrode I2 and with the ground by way of the tap and ground wire 21. A continuous electric potential is thereby established and a continuous uninterrupted direct flow to ground obtained which greatly facilitates the collective action of the electrode I2 with respect to electrostatic fields within the dry cleaning solvent circulated thereover and soil particles therein as well as garments therein.

By referring now to Figure 3 of the drawings the preferred manner of installation of the static discharge device will be seen and it will be observed that a lower corner portion of a dry cleaning machine is indicated by the numeral 30, the solvent therein by the numeral 3| and a fitting 32 establishing communication with the machine 30 so that the solvent 3I may flow outwardly therethrough as indicated by the arrow. A T fitting 33 is connected with the fitting 32 and forms a portion of the normal communication channel between the dry cleaning machine and the filter (not shown). The directional flow of the solvent through the T fitting 33 is indicated by the arrows. The grounding electrode I2 is shown in position in the T fitting 33 and extending into the flow of the solvent therethrough.

In Figure 4 of the drawings an alternate method of installation is illustrated wherein the explosion-proof box I3 with the projecting groundin electrode I2 thereon is shown applied to a straight line type of connection between a dry cleaning machine (not shown) and a filter therefor (not shown). The tubular line communicating with the dry cleaning machine and the filter is indicated by the numeral 34 and the T therein by the numeral 35. The grounding electrode I2 i positioned within the T so that the fluid fiowing within the line 34 and the T 35 will pass thereabout. The direction of flow through the T 35 is indicated by the arrows.

It has been determined that the device and particularly the grounding electrode I2 should be located within the solvent flow at a point immediately adjacent a dry cleaning machine proper and the installation illustrated in Figure 3 of the drawings is therefore preferred.

By referring again to Figure 1 of the drawings it will be observed that as is customary with explosion-proof box mountings, the grounding elec trode I2 is arranged so that a portion thereof having a threaded pattern 36 formed thereon threadably engages a bushing 31 which in turn is engaged in the threaded orifice in the explosionproof box I0. In order that the explosion-proof box and the devices therein may be carried di rectly on the T fitting I3 and hence on the dry cleaning machine, a secondary bushing 38 is threaded on the bushing 31 and threadably engaged in the T fitting l3. Similar threaded connections are employed in connection with a conduit 39 enclosing the circuit wires I9 by means of which the power supply is connected to the device.

It will thus be seen that a simple electronic device has been disclosed which through its ability to eliminate resistance in a ground circuit enables all of the electrostatic charges generated in a dry cleaning machine to be discharged continually and thereby prevents the development of any electrostatic potential in the machine, the solvents therein or the garments therein, which electrostatic potential, if allowed to exist, would result in the immediate redepositation of soil in the garments resulting in the phenomenon known in the dry cleaning art as graying.

The invention disclosed herein thereby eliminates graying and additionally eliminates the necessity of adding moisture to the liquid soaps commonly employed in connection with liquid solvents as well as the necessity of adding mois, ture to the garments as by humidifying cabinets as sometimes practiced in the art.

Additionally, the invention enables a satisfactory dry cleaning operation to be accomplished whereby the garments cleaned will be bright and of true color and completely free of redeposited soil to the end that the actual dry cleaning operation may be effected in considerably less time than has heretofore been believed necessary.

Having thus described my invention, what I claim is: v

1. Static discharge apparatus comprising a rodlike collecting electrode, a power source and a ground, one end of the said electrode connected.

to said ground, a transformer in connection with the said power source and a rectifier in connection with the secondary of the said transformer,

and a conductor connecting the said positive side of said rectifier with the said electrode at a point.

thereon spaced with respect to said ground connection and hence with the said ground by way of said electrode.

2. Static discharge apparatus comprising an elongated collecting electrode, a powersource and a ground, one end of the said electrode connected to said ground, a transformer in connection with the said power source and a rectifier in connection with the secondary of the said transformer, and means connecting the said positive side of said rectifier with the said electrodeat a point spaced with respect to said ground connection thereon with the said ground through'said electrode, and means connecting the negative side of the said rectifier to said ground, said means incorporating a resistance element of approximately 200,000 ohm-s.

ALEX J. CHECK.

References Cited in the file of this patent UNITED, STATES PATENTS Number Name Date 20 940,430 Chapman Nov. 16, 1909 1,394,211 Morgan et al Oct. 18, 1921 2,103,758 Seyfried Dec. 28, 1937 2,333,213 Slayter Nov. 2, 1943 FOREIGN PATENTS 25 Number Country Date 767,652 France July 23, 1934 

